Add ld_list_options
This patch adds ld_list_options for ELF targets to avoid duplicated
outputs from ld --help.
* Makefile.am (ELF_CLFAGS): New.
(AM_CFLAGS): Add $(ELF_CLFAGS).
* configure.ac (elf_list_options): New. AC_SUBST.
(elf_shlib_list_options): Likewise.
(elf_plt_unwind_list_options): Likewise.
* lexsup.c (elf_shlib_list_options): New.
(elf_static_list_options): Likewise.
(elf_plt_unwind_list_options): Likewise.
(ld_list_options): Likewise.
(help): Call ld_list_options.
* Makefile.in: Regenerated.
* configure: Likewise.
* emulparams/plt_unwind.sh (PLT_UNWIND): New.
(PARSE_AND_LIST_OPTIONS): Removed.
* emultempl/elf32.em (gld_list_options): New.
(gld${EMULATION_NAME}_list_options): Define only if BNDPLT or
PARSE_AND_LIST_OPTIONS is defined.
(ld_${EMULATION_NAME}_emulation): Replace
gld${EMULATION_NAME}_list_options with ${gld_list_options.